Character limit in Profile/About?

I've entered a short biographical paragraph in the "About" section of my profile, which in my theme (Enterprise) shows up at the bottom of each post that I author. Only the first 140 characters show up, however, and when I go back to edit my profile page the paragraph is clipped in the About section as well. This happened in my previous theme (MistyLook) as well, and I just assumed there was a 140 character limit. However, this does not happen to the profile of another author on my blog, whose bio is much longer than 140 characters. What's the deal?